1 /* 2 * Copyright (C) 2007-2008 The Android Open Source Project 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17 package com.android.server; 18 19 import android.app.Notification; 20 import android.app.NotificationManager; 21 import android.app.PendingIntent; 22 import android.content.ContentResolver; 23 import android.content.Context; 24 import android.content.Intent; 25 import android.content.pm.IPackageDataObserver; 26 import android.content.pm.IPackageManager; 27 import android.content.pm.PackageManager; 28 import android.os.Binder; 29 import android.os.Environment; 30 import android.os.FileObserver; 31 import android.os.Handler; 32 import android.os.Message; 33 import android.os.Process; 34 import android.os.RemoteException; 35 import android.os.ServiceManager; 36 import android.os.StatFs; 37 import android.os.SystemClock; 38 import android.os.SystemProperties; 39 import android.os.UserHandle; 40 import android.os.storage.StorageManager; 41 import android.provider.Settings; 42 import android.text.format.Formatter; 43 import android.util.EventLog; 44 import android.util.Slog; 45 import android.util.TimeUtils; 46 47 import java.io.File; 48 import java.io.FileDescriptor; 49 import java.io.PrintWriter; 50 51 /** 52 * This class implements a service to monitor the amount of disk 53 * storage space on the device. If the free storage on device is less 54 * than a tunable threshold value (a secure settings parameter; 55 * default 10%) a low memory notification is displayed to alert the 56 * user. If the user clicks on the low memory notification the 57 * Application Manager application gets launched to let the user free 58 * storage space. 59 * 60 * Event log events: A low memory event with the free storage on 61 * device in bytes is logged to the event log when the device goes low 62 * on storage space. The amount of free storage on the device is 63 * periodically logged to the event log. The log interval is a secure 64 * settings parameter with a default value of 12 hours. When the free 65 * storage differential goes below a threshold (again a secure 66 * settings parameter with a default value of 2MB), the free memory is 67 * logged to the event log. 68 */ 69 public class DeviceStorageMonitorService extends Binder { 70 private static final String TAG = "DeviceStorageMonitorService"; 71 72 private static final boolean DEBUG = false; 73 private static final boolean localLOGV = false; 74 75 private static final int DEVICE_MEMORY_WHAT = 1; 76 private static final int MONITOR_INTERVAL = 1; //in minutes 77 private static final int LOW_MEMORY_NOTIFICATION_ID = 1; 78 79 private static final int DEFAULT_FREE_STORAGE_LOG_INTERVAL_IN_MINUTES = 12*60; //in minutes 80 private static final long DEFAULT_DISK_FREE_CHANGE_REPORTING_THRESHOLD = 2 * 1024 * 1024; // 2MB 81 private static final long DEFAULT_CHECK_INTERVAL = MONITOR_INTERVAL*60*1000; 82 83 private long mFreeMem; // on /data 84 private long mFreeMemAfterLastCacheClear; // on /data 85 private long mLastReportedFreeMem; 86 private long mLastReportedFreeMemTime; 87 private boolean mLowMemFlag=false; 88 private boolean mMemFullFlag=false; 89 private Context mContext; 90 private ContentResolver mResolver; 91 private long mTotalMemory; // on /data 92 private StatFs mDataFileStats; 93 private StatFs mSystemFileStats; 94 private StatFs mCacheFileStats; 95 96 private static final File DATA_PATH = Environment.getDataDirectory(); 97 private static final File SYSTEM_PATH = Environment.getRootDirectory(); 98 private static final File CACHE_PATH = Environment.getDownloadCacheDirectory(); 99 100 private long mThreadStartTime = -1; 101 private boolean mClearSucceeded = false; 102 private boolean mClearingCache; 103 private Intent mStorageLowIntent; 104 private Intent mStorageOkIntent; 105 private Intent mStorageFullIntent; 106 private Intent mStorageNotFullIntent; 107 private CachePackageDataObserver mClearCacheObserver; 108 private final CacheFileDeletedObserver mCacheFileDeletedObserver; 109 private static final int _TRUE = 1; 110 private static final int _FALSE = 0; 111 // This is the raw threshold that has been set at which we consider 112 // storage to be low. 113 private long mMemLowThreshold; 114 // This is the threshold at which we start trying to flush caches 115 // to get below the low threshold limit. It is less than the low 116 // threshold; we will allow storage to get a bit beyond the limit 117 // before flushing and checking if we are actually low. 118 private long mMemCacheStartTrimThreshold; 119 // This is the threshold that we try to get to when deleting cache 120 // files. This is greater than the low threshold so that we will flush 121 // more files than absolutely needed, to reduce the frequency that 122 // flushing takes place. 123 private long mMemCacheTrimToThreshold; 124 private long mMemFullThreshold; 125 126 /** 127 * This string is used for ServiceManager access to this class. 128 */ 129 public static final String SERVICE = "devicestoragemonitor"; 130 131 /** 132 * Handler that checks the amount of disk space on the device and sends a 133 * notification if the device runs low on disk space 134 */ 135 Handler mHandler = new Handler() { 136 @Override 137 public void handleMessage(Message msg) { 138 //don't handle an invalid message 139 if (msg.what != DEVICE_MEMORY_WHAT) { 140 Slog.e(TAG, "Will not process invalid message"); 141 return; 142 } 143 checkMemory(msg.arg1 == _TRUE); 144 } 145 }; 146 147 class CachePackageDataObserver extends IPackageDataObserver.Stub { 148 public void onRemoveCompleted(String packageName, boolean succeeded) { 149 mClearSucceeded = succeeded; 150 mClearingCache = false; 151 if(localLOGV) Slog.i(TAG, " Clear succeeded:"+mClearSucceeded 152 +", mClearingCache:"+mClearingCache+" Forcing memory check"); 153 postCheckMemoryMsg(false, 0); 154 } 155 } 156 157 private final void restatDataDir() { 158 try { 159 mDataFileStats.restat(DATA_PATH.getAbsolutePath()); 160 mFreeMem = (long) mDataFileStats.getAvailableBlocks() * 161 mDataFileStats.getBlockSize(); 162 } catch (IllegalArgumentException e) { 163 // use the old value of mFreeMem 164 } 165 // Allow freemem to be overridden by debug.freemem for testing 166 String debugFreeMem = SystemProperties.get("debug.freemem"); 167 if (!"".equals(debugFreeMem)) { 168 mFreeMem = Long.parseLong(debugFreeMem); 169 } 170 // Read the log interval from secure settings 171 long freeMemLogInterval = Settings.Global.getLong(mResolver, 172 Settings.Global.SYS_FREE_STORAGE_LOG_INTERVAL, 173 DEFAULT_FREE_STORAGE_LOG_INTERVAL_IN_MINUTES)*60*1000; 174 //log the amount of free memory in event log 175 long currTime = SystemClock.elapsedRealtime(); 176 if((mLastReportedFreeMemTime == 0) || 177 (currTime-mLastReportedFreeMemTime) >= freeMemLogInterval) { 178 mLastReportedFreeMemTime = currTime; 179 long mFreeSystem = -1, mFreeCache = -1; 180 try { 181 mSystemFileStats.restat(SYSTEM_PATH.getAbsolutePath()); 182 mFreeSystem = (long) mSystemFileStats.getAvailableBlocks() * 183 mSystemFileStats.getBlockSize(); 184 } catch (IllegalArgumentException e) { 185 // ignore; report -1 186 } 187 try { 188 mCacheFileStats.restat(CACHE_PATH.getAbsolutePath()); 189 mFreeCache = (long) mCacheFileStats.getAvailableBlocks() * 190 mCacheFileStats.getBlockSize(); 191 } catch (IllegalArgumentException e) { 192 // ignore; report -1 193 } 194 EventLog.writeEvent(EventLogTags.FREE_STORAGE_LEFT, 195 mFreeMem, mFreeSystem, mFreeCache); 196 } 197 // Read the reporting threshold from secure settings 198 long threshold = Settings.Global.getLong(mResolver, 199 Settings.Global.DISK_FREE_CHANGE_REPORTING_THRESHOLD, 200 DEFAULT_DISK_FREE_CHANGE_REPORTING_THRESHOLD); 201 // If mFree changed significantly log the new value 202 long delta = mFreeMem - mLastReportedFreeMem; 203 if (delta > threshold || delta < -threshold) { 204 mLastReportedFreeMem = mFreeMem; 205 EventLog.writeEvent(EventLogTags.FREE_STORAGE_CHANGED, mFreeMem); 206 } 207 } 208 209 private final void clearCache() { 210 if (mClearCacheObserver == null) { 211 // Lazy instantiation 212 mClearCacheObserver = new CachePackageDataObserver(); 213 } 214 mClearingCache = true; 215 try { 216 if (localLOGV) Slog.i(TAG, "Clearing cache"); 217 IPackageManager.Stub.asInterface(ServiceManager.getService("package")). 218 freeStorageAndNotify(mMemCacheTrimToThreshold, mClearCacheObserver); 219 } catch (RemoteException e) { 220 Slog.w(TAG, "Failed to get handle for PackageManger Exception: "+e); 221 mClearingCache = false; 222 mClearSucceeded = false; 223 } 224 } 225 226 private final void checkMemory(boolean checkCache) { 227 //if the thread that was started to clear cache is still running do nothing till its 228 //finished clearing cache. Ideally this flag could be modified by clearCache 229 // and should be accessed via a lock but even if it does this test will fail now and 230 //hopefully the next time this flag will be set to the correct value. 231 if(mClearingCache) { 232 if(localLOGV) Slog.i(TAG, "Thread already running just skip"); 233 //make sure the thread is not hung for too long 234 long diffTime = System.currentTimeMillis() - mThreadStartTime; 235 if(diffTime > (10*60*1000)) { 236 Slog.w(TAG, "Thread that clears cache file seems to run for ever"); 237 } 238 } else { 239 restatDataDir(); 240 if (localLOGV) Slog.v(TAG, "freeMemory="+mFreeMem); 241 242 //post intent to NotificationManager to display icon if necessary 243 if (mFreeMem < mMemLowThreshold) { 244 if (checkCache) { 245 // We are allowed to clear cache files at this point to 246 // try to get down below the limit, because this is not 247 // the initial call after a cache clear has been attempted. 248 // In this case we will try a cache clear if our free 249 // space has gone below the cache clear limit. 250 if (mFreeMem < mMemCacheStartTrimThreshold) { 251 // We only clear the cache if the free storage has changed 252 // a significant amount since the last time. 253 if ((mFreeMemAfterLastCacheClear-mFreeMem) 254 >= ((mMemLowThreshold-mMemCacheStartTrimThreshold)/4)) { 255 // See if clearing cache helps 256 // Note that clearing cache is asynchronous and so we do a 257 // memory check again once the cache has been cleared. 258 mThreadStartTime = System.currentTimeMillis(); 259 mClearSucceeded = false; 260 clearCache(); 261 } 262 } 263 } else { 264 // This is a call from after clearing the cache. Note 265 // the amount of free storage at this point. 266 mFreeMemAfterLastCacheClear = mFreeMem; 267 if (!mLowMemFlag) { 268 // We tried to clear the cache, but that didn't get us 269 // below the low storage limit. Tell the user. 270 Slog.i(TAG, "Running low on memory. Sending notification"); 271 sendNotification(); 272 mLowMemFlag = true; 273 } else { 274 if (localLOGV) Slog.v(TAG, "Running low on memory " + 275 "notification already sent. do nothing"); 276 } 277 } 278 } else { 279 mFreeMemAfterLastCacheClear = mFreeMem; 280 if (mLowMemFlag) { 281 Slog.i(TAG, "Memory available. Cancelling notification"); 282 cancelNotification(); 283 mLowMemFlag = false; 284 } 285 } 286 if (mFreeMem < mMemFullThreshold) { 287 if (!mMemFullFlag) { 288 sendFullNotification(); 289 mMemFullFlag = true; 290 } 291 } else { 292 if (mMemFullFlag) { 293 cancelFullNotification(); 294 mMemFullFlag = false; 295 } 296 } 297 } 298 if(localLOGV) Slog.i(TAG, "Posting Message again"); 299 //keep posting messages to itself periodically 300 postCheckMemoryMsg(true, DEFAULT_CHECK_INTERVAL); 301 } 302 303 private void postCheckMemoryMsg(boolean clearCache, long delay) { 304 // Remove queued messages 305 mHandler.removeMessages(DEVICE_MEMORY_WHAT); 306 mHandler.sendMessageDelayed(mHandler.obtainMessage(DEVICE_MEMORY_WHAT, 307 clearCache ?_TRUE : _FALSE, 0), 308 delay); 309 } 310 311 /** 312 * Constructor to run service. initializes the disk space threshold value 313 * and posts an empty message to kickstart the process. 314 */ 315 public DeviceStorageMonitorService(Context context) { 316 mLastReportedFreeMemTime = 0; 317 mContext = context; 318 mResolver = mContext.getContentResolver(); 319 //create StatFs object 320 mDataFileStats = new StatFs(DATA_PATH.getAbsolutePath()); 321 mSystemFileStats = new StatFs(SYSTEM_PATH.getAbsolutePath()); 322 mCacheFileStats = new StatFs(CACHE_PATH.getAbsolutePath()); 323 //initialize total storage on device 324 mTotalMemory = (long)mDataFileStats.getBlockCount() * 325 mDataFileStats.getBlockSize(); 326 mStorageLowIntent = new Intent(Intent.ACTION_DEVICE_STORAGE_LOW); 327 mStorageLowIntent.addFlags(Intent.FLAG_RECEIVER_REGISTERED_ONLY_BEFORE_BOOT); 328 mStorageOkIntent = new Intent(Intent.ACTION_DEVICE_STORAGE_OK); 329 mStorageOkIntent.addFlags(Intent.FLAG_RECEIVER_REGISTERED_ONLY_BEFORE_BOOT); 330 mStorageFullIntent = new Intent(Intent.ACTION_DEVICE_STORAGE_FULL); 331 mStorageFullIntent.addFlags(Intent.FLAG_RECEIVER_REGISTERED_ONLY_BEFORE_BOOT); 332 mStorageNotFullIntent = new Intent(Intent.ACTION_DEVICE_STORAGE_NOT_FULL); 333 mStorageNotFullIntent.addFlags(Intent.FLAG_RECEIVER_REGISTERED_ONLY_BEFORE_BOOT); 334 335 // cache storage thresholds 336 final StorageManager sm = StorageManager.from(context); 337 mMemLowThreshold = sm.getStorageLowBytes(DATA_PATH); 338 mMemFullThreshold = sm.getStorageFullBytes(DATA_PATH); 339 340 mMemCacheStartTrimThreshold = ((mMemLowThreshold*3)+mMemFullThreshold)/4; 341 mMemCacheTrimToThreshold = mMemLowThreshold 342 + ((mMemLowThreshold-mMemCacheStartTrimThreshold)*2); 343 mFreeMemAfterLastCacheClear = mTotalMemory; 344 checkMemory(true); 345 346 mCacheFileDeletedObserver = new CacheFileDeletedObserver(); 347 mCacheFileDeletedObserver.startWatching(); 348 } 349 350 /** 351 * This method sends a notification to NotificationManager to display 352 * an error dialog indicating low disk space and launch the Installer 353 * application 354 */ 355 private final void sendNotification() { 356 if(localLOGV) Slog.i(TAG, "Sending low memory notification"); 357 //log the event to event log with the amount of free storage(in bytes) left on the device 358 EventLog.writeEvent(EventLogTags.LOW_STORAGE, mFreeMem); 359 // Pack up the values and broadcast them to everyone 360 Intent lowMemIntent = new Intent(Environment.isExternalStorageEmulated() 361 ? Settings.ACTION_INTERNAL_STORAGE_SETTINGS 362 : Intent.ACTION_MANAGE_PACKAGE_STORAGE); 363 lowMemIntent.putExtra("memory", mFreeMem); 364 lowMemIntent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK); 365 NotificationManager mNotificationMgr = 366 (NotificationManager)mContext.getSystemService( 367 Context.NOTIFICATION_SERVICE); 368 CharSequence title = mContext.getText( 369 com.android.internal.R.string.low_internal_storage_view_title); 370 CharSequence details = mContext.getText( 371 com.android.internal.R.string.low_internal_storage_view_text); 372 PendingIntent intent = PendingIntent.getActivityAsUser(mContext, 0, lowMemIntent, 0, 373 null, UserHandle.CURRENT); 374 Notification notification = new Notification(); 375 notification.icon = com.android.internal.R.drawable.stat_notify_disk_full; 376 notification.tickerText = title; 377 notification.flags |= Notification.FLAG_NO_CLEAR; 378 notification.setLatestEventInfo(mContext, title, details, intent); 379 mNotificationMgr.notifyAsUser(null, LOW_MEMORY_NOTIFICATION_ID, notification, 380 UserHandle.ALL); 381 mContext.sendStickyBroadcastAsUser(mStorageLowIntent, UserHandle.ALL); 382 } 383 384 /** 385 * Cancels low storage notification and sends OK intent. 386 */ 387 private final void cancelNotification() { 388 if(localLOGV) Slog.i(TAG, "Canceling low memory notification"); 389 NotificationManager mNotificationMgr = 390 (NotificationManager)mContext.getSystemService( 391 Context.NOTIFICATION_SERVICE); 392 //cancel notification since memory has been freed 393 mNotificationMgr.cancelAsUser(null, LOW_MEMORY_NOTIFICATION_ID, UserHandle.ALL); 394 395 mContext.removeStickyBroadcastAsUser(mStorageLowIntent, UserHandle.ALL); 396 mContext.sendBroadcastAsUser(mStorageOkIntent, UserHandle.ALL); 397 } 398 399 /** 400 * Send a notification when storage is full. 401 */ 402 private final void sendFullNotification() { 403 if(localLOGV) Slog.i(TAG, "Sending memory full notification"); 404 mContext.sendStickyBroadcastAsUser(mStorageFullIntent, UserHandle.ALL); 405 } 406 407 /** 408 * Cancels memory full notification and sends "not full" intent. 409 */ 410 private final void cancelFullNotification() { 411 if(localLOGV) Slog.i(TAG, "Canceling memory full notification"); 412 mContext.removeStickyBroadcastAsUser(mStorageFullIntent, UserHandle.ALL); 413 mContext.sendBroadcastAsUser(mStorageNotFullIntent, UserHandle.ALL); 414 } 415 416 public void updateMemory() { 417 int callingUid = getCallingUid(); 418 if(callingUid != Process.SYSTEM_UID) { 419 return; 420 } 421 // force an early check 422 postCheckMemoryMsg(true, 0); 423 } 424 425 /** 426 * Callable from other things in the system service to obtain the low memory 427 * threshold. 428 * 429 * @return low memory threshold in bytes 430 */ 431 public long getMemoryLowThreshold() { 432 return mMemLowThreshold; 433 } 434 435 /** 436 * Callable from other things in the system process to check whether memory 437 * is low. 438 * 439 * @return true is memory is low 440 */ 441 public boolean isMemoryLow() { 442 return mLowMemFlag; 443 } 444 445 public static class CacheFileDeletedObserver extends FileObserver { 446 public CacheFileDeletedObserver() { 447 super(Environment.getDownloadCacheDirectory().getAbsolutePath(), FileObserver.DELETE); 448 } 449 450 @Override 451 public void onEvent(int event, String path) { 452 EventLogTags.writeCacheFileDeleted(path); 453 } 454 } 455 456 @Override 457 protected void dump(FileDescriptor fd, PrintWriter pw, String[] args) { 458 if (mContext.checkCallingOrSelfPermission(android.Manifest.permission.DUMP) 459 != PackageManager.PERMISSION_GRANTED) { 460 461 pw.println("Permission Denial: can't dump " + SERVICE + " from from pid=" 462 + Binder.getCallingPid() 463 + ", uid=" + Binder.getCallingUid()); 464 return; 465 } 466 467 pw.println("Current DeviceStorageMonitor state:"); 468 pw.print(" mFreeMem="); pw.print(Formatter.formatFileSize(mContext, mFreeMem)); 469 pw.print(" mTotalMemory="); 470 pw.println(Formatter.formatFileSize(mContext, mTotalMemory)); 471 pw.print(" mFreeMemAfterLastCacheClear="); 472 pw.println(Formatter.formatFileSize(mContext, mFreeMemAfterLastCacheClear)); 473 pw.print(" mLastReportedFreeMem="); 474 pw.print(Formatter.formatFileSize(mContext, mLastReportedFreeMem)); 475 pw.print(" mLastReportedFreeMemTime="); 476 TimeUtils.formatDuration(mLastReportedFreeMemTime, SystemClock.elapsedRealtime(), pw); 477 pw.println(); 478 pw.print(" mLowMemFlag="); pw.print(mLowMemFlag); 479 pw.print(" mMemFullFlag="); pw.println(mMemFullFlag); 480 pw.print(" mClearSucceeded="); pw.print(mClearSucceeded); 481 pw.print(" mClearingCache="); pw.println(mClearingCache); 482 pw.print(" mMemLowThreshold="); 483 pw.print(Formatter.formatFileSize(mContext, mMemLowThreshold)); 484 pw.print(" mMemFullThreshold="); 485 pw.println(Formatter.formatFileSize(mContext, mMemFullThreshold)); 486 pw.print(" mMemCacheStartTrimThreshold="); 487 pw.print(Formatter.formatFileSize(mContext, mMemCacheStartTrimThreshold)); 488 pw.print(" mMemCacheTrimToThreshold="); 489 pw.println(Formatter.formatFileSize(mContext, mMemCacheTrimToThreshold)); 490 } 491 } 492
